Application fatigue may cause various metal, ceramic, and alloy components (e.g., super alloys) to experience wear. For example, cracking, abrasion, erosion, and/or a variety of other conditions may cause the removal or wear of original substrate material. To repair the worn components, filler material may be added (e.g., welded) to fill in cracks, to patch abrasions, and/or to otherwise replace material lost to erosion. Likewise, when joining two or more components together, filler material may be added to the original substrate material of one or more of the components. Filler material that is the same as, or similar to, the substrate material may be used to provide relatively strong uniform mechanical properties across the repaired and/or joined components.
When the filler material is a relatively high temperature performance alloy (e.g., nickel and/or cobalt based super alloys used in relatively hot gas paths of gas turbine engines) that has a relatively high melting temperature, a relatively significant application of energy must be applied to the filler material before the filler material can be applied to the original substrate material. But, the large amount of radiant heat (e.g., produced by a welding apparatus) that is used to melt the filler material may also affect the original substrate material. For example, the impingement of the radiant heat may cause slumping, melting, recrystallization, grain growth, and/or other changes to the microstructure of the original substrate material. Such changes in the original substrate material may reduce the strength, toughness, and/or other mechanical properties of the component(s) being repaired and/or joined together. Moreover, the impingement of the radiant heat on the original substrate material may cause the joint between the filler material and the original substrate material to fracture during cooling, which is commonly referred to as “hot tearing”.
While filler materials with lower melting temperatures may alternatively be used, such filler materials may provide lower performance at high temperatures and/or possess mechanical properties that are increasingly different than the mechanical properties of the original substrate material. For example, a brazing process may impart less heat to the original substrate material. But, the melting point of brazing materials must be lower than the melting point of the original substrate material, which may require the use of melting point suppressing elements (e.g., silicon and/or boron) in quantities that result in the formation of relatively high amounts of brittle intermetallic phases that deleteriously affect the mechanical properties of the repaired and/or joined component(s). What is needed is a technique and system that allow the use of relatively high melting temperature filler material without causing problems with the original substrate material.